Gabriele Cosmo
168 lines
5.5 KiB
Plaintext
168 lines
5.5 KiB
Plaintext
$Id: README,v 1.16 2004/06/23 11:30:51 maire Exp $
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-------------------------------------------------------------------
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=========================================================
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Geant4 - an Object-Oriented Toolkit for Simulation in HEP
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=========================================================
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TestEm2
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-------
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This example allows to do the shower development of an single primary
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particle, and to survey the physics processes which occur,
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with printing and visualization.
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1- GEOMETRY DEFINITION
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The geometry consists of a cylinder of homegenous material.
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This cylinder is replicated longitudinaly (slice) and radialy (ring).
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The default geometry is constructed in DetectorConstruction class,
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but all of the above parameters can be modified interactively via
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the commands defined in the DetectorMessenger class.
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Material can be choosen: Air Water lAr Al Fe BGO PbWO4 Pb.
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eg: /testem/det/setMat PbWO4
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The size of the slices and rings are expressed in radiation length units
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and can be changed.
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eg: /testem/det/setLbin 20 1. ---> 20 slices of 1. radl
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/testem/det/setRbin 5 0.25 ---> 5 rings of 0.25 radl
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/testem/det/update ---> rebuild the geometry
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An uniform magnetic field along the cylinder axis can be set.
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eg: /testem/det/setField 5 tesla
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2- PHYSICS LISTS
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Modular PhysicsList are used. The following modules can be activated:
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1. "standard" - (alternative) standard EM physics
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2. "g4v52" - (alternative) standard EM physics version G4 5.2
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3. "high_energy" - add high energy processes
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To activate a specific module the UI command can be used:
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"/testem/phys/addPhysics title"
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By default "standard" module is loaded.
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3- AN EVENT : THE PRIMARY GENERATOR
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The primary kinematic consists of a single particle which hits the
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cylinder perpendicular to the input face. The type of the particle
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and its energy are set in the PrimaryGeneratorAction class, and can
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changed via the G4 build-in commands of ParticleGun class (see
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the macros provided with this example).
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A RUN is a set of events.
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4- VISUALIZATION
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The Visualization Manager is set in the main().
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The initialisation of the drawing is done via the commands
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/vis/.. in the macro vis.mac. In interactive session:
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PreInit or Idle > /control/execute vis.mac
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The detector has a default view which is a longitudinal view of the
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cylinder.
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The tracks are drawn at the end of event, and erased at the end of run.
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Optionaly one can choose to draw all particles, only the charged one,
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or none. This command is defined in EventActionMessenger class.
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5- PHYSICS DEMO
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The particle's type and the physic processes which will be available
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in this example are set in PhysicsList class.
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In addition a build-in interactive command (/process/inactivate proname)
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allows to activate/inactivate the processes one by one.
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The threshold for producing secondaries can be changed.
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eg: /testem/phys/setCuts 100 microm
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/run/initialize
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6- HOW TO START ?
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- compile and link to generate an executable
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% cd TestEm2
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% gmake
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- execute TestEm2 in 'batch' mode from macro files
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% TestEm2 run01.mac
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- execute TestEm2 in 'interactive mode' with visualization
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% TestEm2
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....
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Idle> type your commands
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....
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Idle> exit
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7- HISTOGRAMS
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TestEm2 produces several histograms:
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Content of these histo:
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1 : energy deposit per event
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2 : charged track length per event
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3 : neutral track length per event
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4 : longitudinal energy profile
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5 : cumulated longitudinal energy profile
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6 : rms of cumulated longitudinal energy profile
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7 : gamma's flux
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8 : positron's flux
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9 : electron's flux
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10 : radial energy profile
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11 : cumulated radial energy profile
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12 : rms of cumulated radial energy profile
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Note that, by default, histograms are disabled. To activate them, uncomment
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the flag G4ANALYSIS_USE in GNUmakefile. To define the output file name with
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histograms and the type of these file the following UI commands can be used:
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"/testem/histo/fileName name"
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"/testem/histo/fileType type"
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The following types are available: "hbook", "XML", "root"
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By default the name is "testem2.paw" and the type "hbook".
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8- Using histograms
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-------------------
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By default the histograms are not activated. To activate histograms
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the environment variable G4ANALYSIS_USE should be defined. For instance
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uncomment the flag G4ANALYSIS_USE in GNUmakefile.
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To use histograms any of implementations of AIDA interfaces should
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be available (see http://aida.freehep.org).
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A package including AIDA and extended interfaces also using Python
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is PI, available from: http://cern.ch/pi .
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Once installed PI or PI-Lite in a specified local area $MYPY, it is
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required to add the installation path to $PATH, i.e. for example,
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for release 1.2.1 of PI:
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setenv PATH ${PATH}:$MYPI/1.2.1/app/releases/PI/PI_1_2_1/rh73_gcc32/bin
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CERN users can use the PATH to the LCG area on AFS.
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Before compilation of the example it is optimal to clean up old
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files:
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gmake histclean
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gmake
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Before running the example the command should be issued:
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eval `aida-config --runtime csh`
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It is possible to choose the format of the output file with
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histograms using UI command:
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/testem/histo/setFileType type
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The following types are available: hbook, root, xml.
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